Fire control for semiautomatic firearms



March 22, 1949. Ru u 2,465,272-

FIRE CONTROL FOR SEMIAUTOMATIC FIREARMS Filed June 15, 1944 Patented Mar. 22, 1949 FIRE EGNTROL FOR SEMIAUTOMATIC FIREARMS Flix Frdric Ruau, Deptford, London, England, assignor to Molins Machine Company, Limited, Deptford, London, England Application June 15, 1944, Serial No. 540,493 In Great Britain June 15, 1943 3 Claims.

This invention concerns improvements in or relating to ordnance and in particular to the firing mechanisms .for ordnance in which rounds are fed automatically into the breech and in which the breech is opened automatically during the run-out or counterrecoil movement of the barrel to eject a spent cartridge and is caused to close automatically on the insertion of a round. Such ordnance is referred to hereinafter for convenience as an automatic gun.

It is an object of the invention to ensure in an automatic gun having a magazine comprising a member movable with the rounds (e. g. a pressure device to feed the rounds), that the firing mechanism will under normal conditions be rendered inoperative after the last round has been rammed. This object is achieved according to the present invention by providing in such an automatic gun having a magazine comprising a member adapted to engage and to be movable with the rounds in the magazine (e. g. a pressure device to feed the rounds), an operative connection between said movable member and a part of the firing mechanism, said part being arranged to be movable from the operative to an inoperative position, said operative connection being arranged to move said movable part to an inoperative position when the movable member has moved to a predetermined position due to the last round having been fed from the receiver. The parts are so arranged that withdrawal of the movable member from the position it occupies after the last round has been fed, will cause the movable part of the firing mechanism to return to an operative position. that when the last round in the magazine has been fed so as to be rammed into the breech the round cannot be fired unless the movable part of the firing-mechanism is returned to the opera tive position. This arrangement ensures that the gunner cannot accidentally fire the gun when there are no more rounds in the receiver. This is an important feature since, if that last round is fired, one round has to be hand-loaded into the breech before it is possible to fire the gun again. Thus although the gunner has control over the firing of the last round, if he is unaware that there are no more rounds left, ordinary manipulatlon of the firingmechanism will show him that the magazine is empty and he can then decide to a charge the magazine with further rounds before firing the round in the breech or, in an emergency, he may decide to fire the last round without placing any further rounds in the magazine.

An automatic gun made in accordance with This arrangement ensures the invention will now be described by Way of example, with reference to the accompanying drawing which shows a side elevation of part of a siX-pounder gun constructed according to the invention.

In the drawing, the parts are shown in the position where the last round has been fed to the breech and the latter has been closed. The gun illustrated is a six-pounder gun having a transverse sliding breech-block provided with scar and firing mechanism. The particular firing mechanism used is the same as that described and illustrated in the co-pending United States patent application Serial No. 495,522. As described in said application the trigger on the breech-block is adapted to be actuated by a pivoted element on the breech-ring 4, the said pivoted element in turn being adapted to be operated by the firecontrol-mechanism in the firing mechanism. As the devices constituting the present invention operate to render the firing mechanism inoperative at certain times it is necessary first to describe the particular form of fire-control-mechanism illustrated and the general operation of the gun in order that the invention may be understood. The breech-block has a breech-openinglever having an arm 5 carrying a roller 6 which is adapted to run up a cam 'l, pivoted on a pin 56 which is fixed on the cradle, during the latter part of the run-out or counterrecoil movement of the, barrel. This arm is fixed on a shaft 8 pivoted in the breech ring t and thereby operates an arm in the interior of the breech ring to open the breech and compress a spring to close the breech all as set forth in the above-mentioned application.

When the breech-block has been opened it is held by catches in the usual manner and after the breech-block is so held the barrel has still further to travel to finish the run-out, and in moving this further distance the roller 6 of the breech-opening-lever engages a pivoted member located on the opposite side of the lever to that adjacent the cam I. This pivoted member comprises a bell-crank lever i5 (having two arms 20 and 2| referred to later) which is pivoted at 16 on the cradle of the gun and adapted to engage a plunger I! to compress a compression-spring it in a tube l9 which is fixed to an extension of the cradle of the gun. The plunger I! has certain functions to perform which do not concern the present invention but the parts are described here because the spring plunger H and cam I together constitute the actuating means for the bell-crank lever l5.

It will be apparent from the description given so far that the arm 2! of the bellcrank lever I5 constituting the pivoted member is raised by the roller 6 of the breech-opening-lever as the latter travels forwardly during the last portion of the run-out.

At the end of the run-out the roller ,6 is still pressing on the arm 2| unless a round has been fed into the breech in which case the breechblock would close and the arm 5 and roller 6 would move down to the position shown in the drawing.

As soon as a round is inserted into the breech and its flange strikes the extractors the breechretaining-catches ar moved clear of the breechblock and the latter is caused to move upwardly by the breech-closing-spring in the usual way. When the breech-block is closed, the arm 5 and the roller 6 move to the position shown in the drawing.

As the gun is fired the barrel with its breechring t recoils and as the roller 6 travels to the right th .cam Tl swings upwards on its pivot 55 to permit this.

The gun is provided with a magazin 3% in which a row of rounds is placed and in which 5 the rounds are fed by means of a spring urged presser-arm iii to a feeding station at which they are engaged by a ramming device (not shown) which rams them in succession into the breech. Such feeding mechanism is not new and is not part of the present invention, but if desired refrence may be made to United States patent application Serial No. 88, 54, and now Patent No. 2,418,856 dated April '8, 1947, for an illustration of the automatic feeding and ramming mechanism. The view shown the accompanying drawing is a view of the gun similar to Figure 5 of the said specification and may easily be compared therewith.

The firing mechanism as previously stated ineludes the usual trigger carried on the sliding breech-block, and the pivoted element which is mounted on the breech-ring and adapted to be actuated to operate the trigger on the breechblock. This pivoted element on the breech-ring is adapted to be moved inwardly by a bellcrank lever 32, pivoted on a pin fixed in a bracket on th breech-ring d, which is part of the fire-control-mechanism, the bellcrank lever in turn being actuated by a push-rod 33 mounted in a pivotally mounted tube 31.; and provided with a cushioning spring 35 to reduce shocks in operation. In the normal operation of the gun, that is to say up to the firing of the last shot, the rear end of this tube 3A is adapted to swing upwardly from a position in which the push-rod is in alignment with a face 36 of the said bellcrank lever in the fire-control-mechanism to a position in which it is out of alignment therewith (i. e. a little lower than the position shown in th draw ing) so that in the latter case the push-rod lies above and on top of the bellcrank lever, and will prevent the pivoted tube from swinging downwardly until the rod is moved to the left, as viewed in the drawing. The tube 34 is pivoted at 3"! on the cradle of the gun to a double-armed lever pivoted on a fixed pivot 38. A rod or cable of any suitable kind is pivoted to the upper arm of the lever at 39 and coupled to liquid-pressure means, e. g. a hydraulic device (not shown) by means of which the lever can be oscillated from the position shown in the drawing to a position where the pivot 39 is moved one inch to the right. The movements take place each time a trigger or similar manually controlled device coupled to the liquid-pressuremeans is operated by the gunner. The clock-wise movement of the double-armed lever in the drawing causes the push-rod and tube to be moved to the left and thus the rod is brought clear of the end of the bell-cranklever 32 which is provided with the face 36 and can fall down into alignment with said race, being guided and controlled in this movement by a slotted bracket 55. The hydraulic pressure is provided by any known means, but is as above stated manually controlled, so that when the piv oted tube is in its lower or operative position and the push rod is in alignment with the aforesaid face 36 of the bellcrank lever another operation of the manual control device will cause the double armed lever to move anti-clockwise and the pushrod to move to the right and strike the face 36 of the bellcrank lever which in turn moves the pivoted element on the breech-ring to strike against the trigger on the breech-block.

In order to ensure that the hydraulic mechanism shall be controlled and manually operated for each shot so as to ensure that th gun is properly laid for each shot, the pivoted tube is provided with an abutment it whichis adapted to engage a cooperating abutment H on the pivoted member 15 previously mentioned. Thus at the end of each run-out the pivoted member i5 raises the pivoted tube of the fire-controlmechanism into the inoperative position and when :th breech-block closes and the bellcrank lever 15 moves down again to the position shown in the drawing it allows the pivoted tube to move downwardly (subject to further control by the position of the presser arm 3| as described later) to the operative position. It will be seen that as the breech-block moves up it causes the roller 6 to move down to the position shown and the pivoted member 15 to swing downwardly under the pressure of the spring '58. It is this lowering of the arm M of the pivoted member which allows the pivoted tube to swing down, provided th rod thereof has been moved to the .left in the manner described.

If, however, the manual control device of the hydraulic mechanism has not been manipulated, so as to move the push-rod and the pivoted tube 34. to the left, then the rod will rest on top of the bellcrank lever 32 so that th fire-controlmechanism is inoperative. However, if and when the hydraulic mechanism is manipulated to cause the rod and tube to be moved to the left after the breech is closed then further manipulation of the hydraulic mechanism will cause the rod to move to the right and strike the bellcrank-lever 32 of the fire-control-mechanism which in turn moves the pivoted element on the breech ring and that in turn operates the trigger on the breech-block.

As previously stated the object of the invention is to ensure that when the last round in the magazine has been rammed into the breech,

that round will not befired unintentionally. This purpose is effected by arranging that the presserarm 31 which feeds the rounds towards the feeding station is operatively connected to the pivoted tube as in such a way that when the presser-arm has moved inwardly to its final position after having fed the last round, the tube 34 and push rod will be raised out of alignment with the face 36 of the aforesaid bellcrank lever of the firecontrol-mechanism, that is to the position shown in the drawing. The arrangement of the parts is such. however, that if the presscr-arm, is withdrawn, then the pivoted tube is lowered into alignment with the bellcrank lever of the fire-control-mechanism. The mechanism for providing this control is constructed in the following manner.

The presser-arm 9! is pivoted on a stud 42 on an extension fixed to the cradle of the gun and the boss 43 of the arm is provided with a projecting pin :34. When the presser-arm is nearly at the inward limit of its feeding stroke the pin engages an arm 45 of a bellcrank-lever pivoted at 46 on the said extension. The other arm 41 of the lever is provided with a pin or roller 48 which works in a slot 49 in a lever 59, which is pivoted at 5! on the said extension. The free end of the lever is pivoted at 52 to a link 53 the other end of which is pivoted at 54 to the end of the tube 34. This arrangement thus ensures that when the last round under the control of the presserarm has been fed into the breach, the gunner, if he desires to fire the round, must pull the presserarm outwardly to allow the pivoted tube to move down. It is desirable that he should be prevented from firing the last round unintentionally since if that round is fired it is necessary to reload the gun manually as described in United States patent application Serial No. 483,454, and now Patent No. 2,418,656, dated April 8, 1947, and fill the magazine with further rounds before it is possible to make use of the automatic feeding and ramming devices. The arrangement, however, does still leave the firing of the last round under the control of the gunner and, if he finds it necessary to fire that last round or desires to do so, he can do this by first withdrawing the pressure-arm and then operating the manual control device of the hydraulic mechanism.

It will be understood that the invention can be applied to any automatic gun having a round magazine, and that the control of the firing mechanism can be efiected by any member or feeler movable with the rounds, and that this member need not be a presser-arm such as that described with reference to the accompanying drawings.

In the copending United States patent application Serial No. 540,494, the last shot control device claimed herein per se is claimed in combination with a manual control device for firing each shot, the manual fire control also being claimed per se in the same application, while in the copending United States patent application Serial No. 540,492 the subject of the present application is claimed in combination with the said manual fire control device and with an auxiliary breechclosing spring arrangement for efiecting rapid closing of the breech. The auxiliary breechclosing spring arrangement is also claimed per se, and in combination with the manual fire control without reference to the last shot control device, in said application Serial No. 540,492.

What I claim as my invention and desire to secure by Letters Patent is:

1. In an automatic gun having a magazine, a firing mechanism having a movable part, means mounting said part for movement from an operative position wherein it may be operated to effect firing of the gun to an inoperative position, a movable member associated with the magazine and movable with the rounds therein, and an operative connection between said movable member and said movable part and operable to move said movable part to its inoperative position when said movable member reaches its position corresponding to the last round in the magazine having been fed therefrom, said operative connection including means manually operable to withdraw said movable member from its last named position to return said movable part to its operative position and thereby permit said last round to be fired.

2. In an automatic gun having a magazine, a firing mechanism having a movable part, means mounting said part for movement from an operative position wherein it may be operated to effect firing of the gun to an inoperative position, a movable member associated with the magazine and movable with the rounds therein, said movable member including a retractable pressure device ior feeding the rounds from the magazine in succession, and an operative connection between said movable member and said movable part and operable to move said movable part to its inoperative position when said movabl member reaches its position corresponding to the last round in the magazine having been fed therefrom, said movable member being manually movable from its last named position to return said movable part to its operative position and thereby permit said last round to be fired.

3. In an automatic gun having a, magazine, a firing mechanism having a movable part, means mounting said part for movement from an operative position wherein it may be operated to effect firing of the gun to an inoperative position, a movable member associated with the magazine and movable with the rounds therein, and an operative connection between said movable member and said movable part and operable to move said movable part to its inoperative position when said movable member reaches its position corresponding to the last round in the magazine having been fed therefrom, said movable member including a part moving therewith and said connection including means engaged by said last named part and connected to said first named movable part for holding the latter in its inoperative position as long as said movable member occupies its last named position, said movable member being manually movable from its last named position to return said movable part to its operative position and thereby permit said last round to be fired.

FELIX FREDERIC RUAU.

REFERENCES CITED The following references are of record in the file of this patent:

Joyce July 5, 1938 

